import sys, pygame,os
from pygame.locals import *
pygame.init()

size = width, height = 1024, 640
speed = [2, 2]
black = 255, 255, 255

screen = pygame.display.set_mode(size)

ball = pygame.image.load("ball.jpg")
ballrect = ball.get_rect()

while 1:
   for event in pygame.event.get():
      if event.type == pygame.QUIT:
         sys.exit()

   ballrect = ballrect.move(speed)
   if ballrect.left < 0 or ballrect.right > width:
      speed[0] = -speed[0]
   if ballrect.top < 0 or ballrect.bottom > height:
      speed[1] = -speed[1]

   screen.fill(black)
   screen.blit(ball, ballrect)
   pygame.display.flip()
